Analysis on Relationship between Influenza Incidence and Temperature in Nanjing

Objectives To analyze the relationship between the incidence of influenza and meteorological factors in Nanjing.

Methods The daily number of cases suffered from influenza-like illness (ILI) and meteorological data in 2010-2013 were obtained. A distributed lag non-linear models (DNLM) was used to analyze the relationship between ILI and temperature.

Results The peak season of ILI was in autumn and winter, mainly among adolescents and children aged < 15 year-old, accounting for 81.80% of total cases. The relative risk of occurring influenza-like illness in Nanjing was the highest when the daily average temperature was 14℃; it was the lowest when the daily average temperature was 25℃ and 1℃; and the relative risk was 74% and 75% when the daily average temperature was 16℃. The number of cases suffered from influenza-like illness was increased rapidly when the daily average temperature was lower than 1℃ or higher than 25℃. There was a lag effect of temperature on the incidence of influenza-like illness.

Conclusions There was a significant relationship between the daily average temperature and the number of cases suffered from influenza-like illness.